Power lifting mechanism for saw-trimmers.



I. L. SKEITH 81 W. B. BURROWS. POWER LIFTING MECHANISM FOR SAW TRIMMERS.APPLiCATION FILED AUG.I8, I910. 1,267,130.

Patented May 21, 1918.

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y m .52 4 l I 5/ F2; 12. 61 a: h 1 6'0 51 1 I M/flesses zyrw' l. L.SKEITH & W. B. BURRLOWS. POWER LH-HNG MECHAHSM EUR SAW TRIMMEHS.

APPLICATION FIL'D AUG. I8, 1910. 1,267, 1 30. Patented May 21, 1918.

- 4 SHEETS-SHEET 2. a

- IZorney I. L. SKEITH & W. B. BUHROWS. POWER LIFTING MECHANISM FOR SAWTRIMMERS APFLICAT'ON FILED AUGIB. 9K0- 1,267,130.

4 SHEETS-SHEET 3.

Witnesses: D

Patented May 21, 1918.

I. L. SKEITH & W. B. BURROWS. POWER LIFTING MECHANISM FOR SAW TRIMMERS.

APPLICATION FILED AUG. I8. 1910. 1,267,130. atented May 21, 1918.

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UNITED STATES PATENT OFFICE.

ISAAC L. SKEITI-I AND WILLIAM B. BURBOWS, OF VANCOUVER, BRITISHCOLUMBIA, CANADA, ASSIGNORS TO SUMNER IRON WORKS, OF EVERETT,WASHINGTON.

Specification of Letters Patent.

Patented May 21, 1918.

Application filed August 18, 1910. Serial No. 577,855.

To all whom it may concern:

Be it known that we, ISAAC L. SKEITH, a subject. of Great Britain,residing at Vancouver British Columbia, Canada, and WIL- LIAM Bmmows, acitizen of the United States, residing at Vancouver, British Columbia,have invented a new and useful Imrovement in Power Lifting Mechanismsfor S KWTIlHImBIS, of which the following is a specification.

Our invention relates to an improvement in power liftin mechanisms forsaw trimmers and comprises the novel parts and combinations of partswhich will be hereinafter described and particularly pointed out in theclaims.

The object of our invention, broadly stated, is to improve and simplifythe construction and operation of such devices.

Specifically, our object comprises a construction such that valvescontrolling the admission and exhaust of air from and supply of air tothe lifting cylinders, are placed directly upon the cylinders so thatthe clearance is minimized and such valves operated from a distant pointb a mechanical connection. By this plan the lar e waste of air caused bythe necessity for filling the pipes extending from the cylinders to thecentral control point every time the saw is lifted, is avoided. y

, Another specific object of our invention is to provide automaticmeans, controlled by the valve-controlling mechanism, whereby when a sawis lifted it will be prevented from droppin until the controllingmechanism has been placed in release position, even should the airpressure entirely fall. This comprises a mechanical catch controlled bythe means employed for setting the valve so that it and the valvefunctionally agree.

Our invention also comprises specifically, a construction of operatinglevers by which each individual saw may be raised or lowered as desiredand, in connection with this, a master lever to which any number ofindividual levers may be connected for simultaneous operation asdesired.

Our invention further specifically comprises a novel construction inthe; means employed for sup ortmg and swinging the saw into and out ocperatlon.

The further objects of, car invention will be disclosed by a study ofthe specifications and claims terminating the same.

In the drawings we have shown our in- IZention embodied in the form nowpreferred y us.

Figure 1 is longitudinal section throu h one of the pneumatic cylindersemployed or controlling a saw.

Fig. 2 is a section on the broken line X of Fig. 1.

Fig. 3 is a section on the line Y Y of Fig. 1.

Figs. 4 and 5are, respectively, side and end elevations of the bank ofcontrolling levers.

Figs. 6 and 7 are, respectively, side and edge elevations of one of theindividual saw controlling levers.

Fig. 8 shows in plan and diagrammatically, the general arrangement ofthe parts and the connection with the" central controlling station.

Fig. 9 shows the arrangement of the entire apparatus in side elevation.

Fig. 10 is a plan view of one of the frames carrying a saw.

Fl 11 is a side elevation of the swinging saw frame.

Fig. 12 is an end view of the three-armed lever which operates thevalve.

Figs. 13 and 14 are, respectively, plan and elevation of catch-releasincam or tappet.

Fig. 15 is a. side elevation of the spring catch for the master lever.

It has been common, heretofore, to control a bank of trimmer saws bysupplying the individual frames, which each carries one of the saws,with a pneumatic cylinder so connected; thereto that the saw may belifted into or out of operating position by admitting air to suchcylinder. In such devices the valves] for t e various cylinders havebeen located at the central controlling point, which point mustnecessarily be at some distance from the cylinders. Such method meansthat whenever a cylinder is thrown into operation, the pipe, extendingfrom the central oint of control to the cylinders, must be lled with airunder pressure, which air is not essential to the proper action of thepiston but simply serves to fill the pipe and communicate t e pressure,and is wasted every time the cylinder is put into use. As a result thereis a large and unnecessary waste of compressed air, making it necessaryto employ an air compressor of much larger capacity than would berequired if this excessive clearance could be eliminatcd.

In our present invention we have placed the valves directly upon thecylinders, so that the clearance between the valve and the cyinder isalmost entirely eliminated, and then control these valves bymechanicalconnection with the distant oint of control. This results in a materiasaving in the amount of comfressed air required.

In devices 0 this character it is customary to have the saws mounted inswinging frames so that the saw will drop by gravity into operatingposition and Wlll be lifted out of operating position by the action ofthe cylinder thereon.

We have provided means whereby when any individual saw frame is liftedout of operating position, a mechanical catch will be automaticallythrown into acting position and so held until the regular controllingmechanism for this saw is placed in release osition, so that if thepressure in the cylin er should drop from any cause, such for instanceas the stoppage of machinery, the saw will not drop into operativeposition until such mechanical catch has been released. The use of thiscatch prevents the belts by which the saws are operated from beingstrained at their maximum tension when the saws are not in use, whichobjection applies to such devices as are not posi-' tively held out ofoperative position when the ressure in the cylinder is removed.

e have also provided means for operating the cylinder valve from adistance, such as will permit the connection of the operatin meansthereto at any angle desired.

n the drawings Fig. 1 shows the longitudinal section of the cylinderwith the valve and the means for operating the same. The cylinder 1 issingle acting, that is, the power the piston to move it in one directiononly, which as shown is during the upward stroke. The piston 2 may be ofany suitable or desired construction.

The cylinder is provided with an inlet port 10, located at the extremelower end of cylinder, and an exhaust port 1.1 located some littledistance above the lower end of the cylinder and so thatit will becovered by the piston in its downward stroke before it can strik thelower head. In this way a certain amoiggriizuir contained in thecylinder is trapp (1 serves as a cushion to prevent the piston fromstriking hard against the lower end of the cylinder.

To prevent dangerous striking of the piston against the upper cylinderhead, we

place the relief port 17 a short distance below the cylinder head whereit will be covered by the piston before finishing its stroke thustrapping enough air to cushion the piston. By controlling the size ofthis port the rate of upward movement of the piston may be controlled,the small port acting to delay the escape of the air.

The piston rod 20 extends through the lower end of the cylinder and isconnected with the rod 21 which is in turn secured to the swingin sawframe either directly or by means 0 interposed mechanism. As shown, theconnection consists of a turnbuckle 21 and rod 25.

We have provided means by which the saws will be mechanically locked andheld in raised position in case the pressure in the cylinders is drop edbelow that necessary to support them. he means preferred and hereinshown is as follows:

Upon the lower end of the piston rod 20, which projects from thecylinder, is secured a disk or cam 23 the periphery of which is ofconical shape with the base downward. We have shown this as being a partof the crosshead or pivotal connection with the rod 21, although this isnot an essential feature. The lower surface 22 of this disk is concavenear its edge so as to more securely engage with the point of thelocking hook. This hook is pivoted at 40 between ears beneath andforming a part of the cylinder. The up er, engaging surface 41 of thehook is slig tly recurved so as to cooperate with the curved undersurface of the disk 22 and thereby assure against release, once they arebrought into engagement except by the positive action of the releasinmechanism. The surface 42 of the side 0 the hook extending below theengaging surface 41, and facing toward the disk 23 is inclined in such away that it will cooperate with the inclined or coned peripheral surfaceof the disk, so that the disk in raising will push the hook outwarduntil it has passed the same, whereupon the hook will swing toward thepiston rod under the influence of gravity, the point 41 swinging beneathsaid disk so as to prevent its falling until the hook has beenpositively thrown outward.

At its upper end the hook 4 is provided with a side extension having itsend surface 43 so inclined and positioned as to engage with theeccentric or cam disk 32 carried by the lower end of the valve 3. Whenthe valve 3 is moved downward into the admission position, the disk 32frees the book so that 1t may drop by gravity into its locking position.

The valve 3, in the form shown and preferred, is a piston valve,consisting of a round bar which is reduced in area attwo pomts 30 and31, so as to provide a suitable area for the passage of steam betweenthe supply chamber 12 and the port 10, and also be carried by intooperative position the belts between the two exhaust ports 11 and 13.The position of the valve shown in Fig. 1 is that in which thecompressed air is in communication with the interior of the cylinder.Compressed air from the suppl chamber 12 passes around the section 30 0the valve to the port 10, and thence directly into the cyl inder, actingto raise the piston to the top of the cylinder.

The lower end of the valve 3 projects through the walls of the cylinderand has a tappet secured thereto, this as shown consisting of aneccentric or cam disk 32, which, in the admission position of the valve,is engaged by that portion of the inclined surface 43 of the hook, whichis nearest the pivot 40.

If now the valve be raised, the first result will be that the movementof the tappet disk 32 over the inclined surface 43 of the hook willswing the point 41 from beneath the disk 23 thus leaving the piston freeto fall.

The disk 23 is slightly above the point 41 of the hook when the pistonis in its uppermost position, so that the weight of the piston and theload carried thereby will never the hook, unless the air pres-- sureshould dropr below that required to carry the load. he swinging of thehook clear of the disk does not, therefore, require the use of anymaterial force.

The next result caused by the raising of the valve is to cut oil thesuppl of compressed air to the cylinder by c osing the port 10. Thevalve is given suflicient lap that exhaust does not commence until afterthe valve has moved a certain distance after closing the admission port.This gives sufficient travel that the hook point 41 is clear of the disk23 before exhaust commences. This takes place through port 11, about thereduced section 31 of the valve and through port 13.

In order to control therate of exhaust and prevent the rapid dropping ofthe piston we provide what may be called a throttle bolt 110, whichassesthrough the wall of the cylinder and into the exhaust ort 11. Thisbolt is clearly shown in Fi It is evident that by screwing this bo tinward it will reduce the area of this exhaust ort, which reduction ofarea may be carried to such a point as will throttle the exhaust so asto make the rate of fall of the piston whatever desired.

he saws are mounted upon swing frames in such a manner that when the sawis raised out of o erative position the belts are slackened, an whenthey are dro ed are tig tened, consequently if the saws be maintained intheir raised position, in which the belts are slackened, by positivemechanical meansin which position the belts are freed from strain, itwill. not be necessary to cut and tighten them at frequent intervals,and

they will therefore last much longer. These mechanical locking meansabove described are controlled directl by the action of the valvescontrolling t e power mechanism, being freed as the first step of themovement of the valve mechanismv to its release position.

To the upper end of the valve 3 which extends to the exterior of thevalve chamber is secured a rod 33 by which the valve is operated. Wehave provided a means for operating these valves which will permit ofleading the actuating wires in any angular direction desired. Thesemeans comprise an arm which is pivoted in direct line with the axis ofthe valve and upon which is mounted a double elbow or three-armed lever,one end of which is connected with valve rod 33, the pivot connectionbeing in line with the axis of the valve and in line with the pivot ofthis swinging arm.

At the end of the cylinder opposite that which contains the valve and inline with the axis of this valve is mounted a pivot bolt 50 upon whichis pivoted an arm 5. This arm is preferably made hollow and, as shown,between the sides thereof is placed a double elbow'or three armed lever6, one arm 60 being pivotally connected with the upper end 0 the rod 33and of such length as to move in a small are which does not materiallydiverge from an exact alinement with the axis of the valve.

The arms 62 and 63 of these levers extend oppositely from the centralpivot 61 and are provided with the means at each end, consisting ofholes or projecting pins, 64, to which may be connected whatever meansare employed for communicating the motion thereto from a distant point.

The means preferred by us for this urpose consists of small piano wires,w ich may be conducted around corners in any course desired by means ofsimple guide pulleys. We prefer to provide t e swin stops which will eas to limit P 85 screwed osition ing pivot arm 5 with engaged by theelbow lever 6, so its motion in any direction. Such shown, consist ofset screws 51 through a portion of the lever in a to be engaged by arms62 and 63 of Two wires 52 and 53 are connected with the opposite arms ofeach of these levers and lead to the central control int.

-At a central control point is provided a batik of controlling levers,one for each cylinder employed, which levers are each connected by meansof these wires with its respective lever 6 carried by the cylinders. Wealso provide a master lever and means b which any number of individuallevers may be connected so as to be operated by and in unison with themaster lever.

These operating levers ars shown in Figs.

ever 6.

the master lever are pivoted upon a common shaft 7, which shaft issupported by brackets or in any other suitable manner. The individuallevers 71 are provided with arms 72 which extend oppositely from thepivot, and to the outer ends of which are connected the wires 52 and 53,which extend to the lovers 6 mounted upon the different cylinders. Thelevers 71, by which the individual saws are operated, are mountedloosely upon shaft 7 Secured to the shaft 7, preferably at each endthereof, are master levers 8. These master levers are also connected bya rod 80 which extends throu h slots 73 formed in each one of theindividual levers 71. These slots 73 are of suflicient transverse lengthto permit of each lever being operated so as to control its valve,without mov in the master lever.

hese slots in the lever may be made of a permanent character closed ateach on We prefer, however, to make them open at one end and thenprovide means, for instance the pivot latches 74, by which this and mabe made open or closed as desired. Suc levers as have their latches 74in position to' close the slots will be operated simultaneously bymovement of the master lever in either direction, while such levers ashave their latches dropped, so as to leave these ends of the slots open,would not be operated by movement of the master lever in one direction.It often happens in operating a bank of trimmer saws that it is desiredto operate certain combinations of saws simultaneousl The alioveexpedient makes it possible for the operator to connect any combinationas is desired for simultaneous operation by the master lever and to varythis combination at any time desired. By moving the master lever in thedirection in which all the slots 73 are permanently closed, all the sawswill be raised while movement in the opposite direction will lower onlythose saws whose individual lovers have their latches 74 in position toclose their slots.

In operating a master lever this must be given a movement sufficient toengage the rod 80 with the end of the slots in the individual leversbefore any movement of the valve is started. The master lever, therefore, has a greater swing than the individual levers.

In Fig. 5-the lever 71 is shown in full lines in one extremeposition andby dotted lines in the other extreme position. The master lever is shownin full lines in its ino erative or central position and by dotted inesin both extreme or operating positions. The master lever is providedwith means by which it is held in central position until it is desiredto move it; such means as shown consisting of a pin 81 projectinglaterally so that when the frame 9 is raised from the lever and a springcatch 82 having a recess or hollow 83 adapted to engage such pin andfurnish'sufiicient resistance to prevent movement of the lever unlesssome little power is applied thereto.

In Fig. 8 we have shown a numbe of cylinders 1 connected by means ofunions 1 and short pipe sections 15, with a main supply pipe 16. Thismakes a very simple and cheap method of supplying the air to thesecylinders as compared with the plan having separate supply pipes fromthe central control station to each cylinder. We also show a series ofwires 52 leading from these cylinders to a central controlling stationA. This view is very diagrammatic in character.

In Fig. 9 is shown, in elevation, the entire apparatus. The wires 52,53, may be led about wheels or pulleys 5a to the central controllingstation 103 where they are connected with the arms 72 of the individualcontrolling levers. Each wire should have a turnbuckle 55 therein sothat its length maiy be adjusted.

11 Figs. 10 and 11 we have shown a plan for mounting saws in swingingframes which permit of adjustment to take up the stretch occurring inthe driving belt, as well as for alining the saw so as to get exactspacing between the saws of the set. This mechanism comprises a frame 9in one end of which a saw, 100, is mounted, which frame is pivoted at 90to arms 91 which are pivoted at their upper ends by pivots 92 tobrackets 93 secured to the end timber 94.

The driving pulleys 95 for all the saws of the set are mounted upon ashaft 96 which is journaled to the timber 94. To the lower pivot 90 ofthis device is secured eye bolts 97, which pass throu h iopenings in thetimbers and are provi ed with nuts 98, by the adjustment of which theseeye bolts may be projected or withdrawn as may be necessary forlengthening the belts, or adjusting the position of the saw relative tosaws. The lateral adjustment or alinement of the saws is varied byunequal adjustment of the bolts 97. Adjustment of the bolt 97 at oneside of the frame without any adjustment of the corresponding bolt uponthe other side would swmg the outer end of the saw frame laterally.

' The shaft 96 is higher than the pivot 90 it will tend to slacken thebelt 99 by which the saw is driven. When the frame is lowered to lacethe saw in operative position the belt 13 tightened. As the saws occupythe raised position more time than they do the lowered the belts isthereby much Weclaim as our invention 1. A lifting mechanism for trimmersaws,

comprising a series of cylinders and pistons the other I therein, eachconnected with its individual saw, a valve carried by each cylinder and.adapted to control the piston therein, a series of levers andconnections therefrom, each to its articular cylinder valve, each ofsaid levers iiaving a transverse slot, a master lever, and a rod carriedby said master lever and adapted to lie in said slots of the individuallevers, whereby the individual levers may be operated separately and aseries of said individual levers may be operated simultaneously by themaster lever.

2. The combination with a series'of saws, of saw-lifting mechanismcomprising a corresponding series of compressed air cylinders eachhaving its piston connected with its saw, valves mounted adjacent to thecylinders, respectively, and each controlling the piston-actuating fluidfor its cylinder, and manually operated means at a distant station forcontrolling all said valves.

3. A lifting mechanism for saw trimmers, comprising a series ofcylinders and pistons therein each connected with its individual saw toraise and lower the same, valves mounted adjacent to said cylinders,respectively, and controlling the fluid for actuating the correspondingpistons, means for mechanically transmittin power from a distant stationto each of said valves, and manually operated selective devices at saidstation for governing the transmission of power to the several valves.

4. A lifting mechanism for trimmer saws, comprising a series ofcylinders and pistons therein, each connected with its individual saw, avalve carried by each cylinder and adapted to control the pistontherein, a series of levers and connections therefrom, each to itsparticular cylinder valve, and a master lever whereby the saws may beraised and lowered at will individually or collectively.

5. A lifting mechanism for trimmer saws, comprising a series ofcylinders and pistons therein, each connected with its individual saw, avalve carried by each cylinder and controlling the movement of thepiston therein, a series of distant controlling levers,

a connection from each of said levers with the valve of its particularcylinder, said levers each having a transverse slot provided with meanswhereby one end of said slot may be closed or opened at will, and amaster lever whereby thesaws may be raised and lowered at willindividually or collectively. 6. A lifting mechanism for trimmer saws,comprising/a series of saws, means for supporting and swingin the sawsinto and out of posltion indepen ently of each other, a series ofoperating levers corresponding with the saws, and a master lever wherebthe saws may be raised and lowered at wi l individually or collectively,a cylinder with piston mounted above each saw, a valve upon eachcylinder for controlling the piston and connected by actuating wires totheir respective levers located at a distant point of control.

7 A lifting mechanism for trimmer saws, comprising means for moving thesaws into and out of operating position, a separate cylinder and pistonfor each saw, and a controlling valve mounted on each cylinder, a seriesof operating levers and a master lever located at a distance from saidcylinders, and mechanical valve-operating connections, as a wire,extending from each operating lever to its respective Valve.

8. In a lifting mechanism for trimmer saws, a cylinder and pistontherein for each saw, said cylinders having the seats for the fluidcontrolling valves formed integrally therewith, a valve for eachcylinder coacting with the seat for said cylinder, and means forcontrolling said valves from a common point.

9. In a lifting mechanism for trimmer saws, a separate cylinder andpiston therein for each saw, said cylinder havin a valve seat formedtherein, a valve in said seat, a valve operating lever mounted upon thecylinder to swing upon double pivots having axes which are atsubstantially right angles, distant operating means, and transmittingmechanisms connecting said operating means with the cylinder-carried,valve-operating levers and radiatin from a common point to the variouscylin ers.

10. In a lifting mechanism for trimmer saws, a separate cylinder andpiston therein for each saw, each cylinder having a valve seat formedthereon, a valve seating u on said seat, and a valve-controlling mem ercarried by the cylinder, said valve-controlling member beingautomatically adjustable to conform to the lead of a transmission memberthroughout a wide angular range.

11. In a lifting mechanism for saw trimmers, the combination withseparate actuating mechanisms for each saw, each of said actuatingmechanisms comprising a cylinder and piston, a valve controlling theactuating fluid and a means for controlling said valve, all mounteddirectly upon the cylinder as a frame, of a corresponding set of distantsecondary controlling mechanisms, one for each cylinder, transmissionmembers connecting said secondary controlling members with the primaryvalve-controlling members carried by the cylinders, a master controllingmember associated with said set of secondary controlling members, andmeans for optionally combining said secondary controlling members forsimultaneous o ration by said master member in any com ination desired,without affecting their capacity for independent and separate action.

12. A shifting mechanism for trimmer saws comprising a series of sawshifting cylinders, a valve seated in the body of each of said cylindersand controlling the supply of motive fluid, each for its respectivecylinder, and a selective operating mechanism for said valves located ata common point.

13. A shifting mechanism for trimmer saws comprising a series of sawshifting cylinders, a valve seated in the body of each of said cylindersand controlling the supply of motive fluid, each for its respectivecylinder, a valve shifting mechanism for each cylinder pivotally mountedupon that cylinder to automatically adjust itself to an actuatinconnection from variable an les, manna ly controllable actuating mem ersgrouped at a common point and transmitting members connecting saidmanually controllable members with the valve shifting mechanism carriedby the cylinders, and means for combining said manually controllablemembers to actuate any desired combination thereof as a unit.

14. A shifting mechanism for trimmer saws comprising a series of sawshifting cylinders, a valve seated in the body of each of said cylindersand controlling the supply of motive fluid, each for its respectivecylinder, a valve-shifting mechanism for each cylinder pivotally mountedu on that cylinder to automatically adjust itself to an actuatingconnection from variable angles, manually controllable actuatin membersgrouped at a common point an transmittin members connecting saidmanually contro lable members with the valve-shifting mechanism carriedby the cylinders.

15. A lifting mechanism for trimmer saws comprising a cylinder, a pistontherein, a piston rod, a connection from the exterior end of said rod tothe saw frame to lift it, a dog engaging member or catch carried by theouter part of the piston rod, a dog pivoted to the cylinder and adaptedto swing under said catch member by gravity, and means for releasingsaid dog from the catch actuated by the valve whlch controls the supplyof actuative fluid to the cylinder.

16. In a lifting mechanism for trimmer saws, a cylinder, a pistontherein, a valve controlling the actuative fluid, means connectingthepiston with the saw, a mechanical catch comprising one member carried bythe cylinder and another connected with the piston and adapted forautomatic lockin engagement, and means for operating %1oth valve andcatch from a distance.

17. In a lifting mechanism for saws, a cylinder, 9. piston therein, avalve controlling the actuative fluid, means connecting the piston withthe saw, a mechanical catch comprising one member carried by thecylinder and another connected with the piston and adapted for automaticlocking engagement, means for operating the valve from a distance, andmeans whereby the movement of the valve into exhaust position willrelease the catch.

18. In a lifting mechanism for trimmer saws, a fluid pressure cylinder,a piston therein, a piston rod, a valve carried directl upon that end ofthe cylinder from Whic the piston rod projects, a locking catchautomatically engageable to hold the piston when raised and comprisingone member carried by the piston rod and another carried by thecylinder, one of said catch members and the valve having parts engagingto release the catch when the catch is placed in release position.

ISAAC L. SKEITH. WILLIAM B. BURROWS.

Witnesses:

Sonnrnnn Dorm, C. DUDLEY Lnn.

trimmer

